NEWER ADVANCES IN LAGuided By:Dr. Anish Tiwari Dr. Adarsh Deshi Dr. Ravi Kalola

INTRODUCTION•Although LA remains the backbone of pain

control in dentistry, research has continued in both medicine and dentistry to seek new and better means of managing pain associated with many surgical treatments

•There are improvements in :1.Safer needles and syringes2. Techniques of regional nerve block3. Newer drugs

pH alterations•The pH of plain LA solution is appx.

5.5,whereas that of vasopressor containing solution is about 4.5

•The addition of substances to the anesthetic that alkalinize the solution should make drugs administration more comfortable

•At higher pH anesthetic drugs should have more rapid onset of action and greater potency

DENTAL LA CARTRIDGE INSERTED INTO MIXING PEN

Addition of sodium bicarbonate to LA•It alkalinizes the solution•Increases the uncharged base molecules •Because of uncharged base molecules

penetration of LA into nerve will be faster•Also it will have rapid onset of action and

greater potency

Addition of CO2•It enhances diffusion of LA through nerve

membrane providing a more rapid onset of nerve block

•As CO2 diffuses through the nerve membrane , intracellular pH is decreased ,raising the intracellular concentration of charged cations , the form of anesthetic that attaches to receptor sites in sodium channels

•Because the cationic form of the drug does not readily diffuse out of the nerve , the anesthetic becomes concentrated, providing a longer duration of anesthesia

•The problem clinically has been that if the carbonated local anesthetic agent is not injected almost immediately after opening the vial, the CO2 will diffuse out of the solution ,significantly diminishing its effectiveness

LOCAL ANESTHESIA•CENTBUCRIDINE•ROPIVACAINE•EMLA (EUTECTIC MIXTURE OF LOCAL

ANESTHESIA )•ULTRA-LONG ACTING ANESTHSIA

1.TTX(TETRODOTOXIN) 2.STX(SAXITOXIN)

CENTBUCRIDINE• Quinoline derivative• 5-8 times more potent then lidocaine• Rapid onset and equivalent duration of

action• Does not affect CNS and CVS except in

larger doses• Used in subarachnoid , extradural

anestheasia,intravenous regional anesthesia and intraocular surgery

ROPIVACAINE•Long acting amide anesthetic•Similar to bupivacaine and etidocaine in

duration of activity•Structurally similar to mapivacaine and

bupivacaine•Decreased cardiotoxicity •Used for regional nerve block

EUTECTIC MIXTUTRE OF LA

•Oil in water emulsion containing high concentration of lidocaine and prilocaine in base form

•Consists of 5% cream containing 25mg/g lidocaine and 25mg/g prilocaine

•Provides anesthesia of intact skin profound enough to permit venipuncture to performed painlessly

TETRODOTOXIN AND SAXITOXIN

•Ultra long acting la•Blocks sodium channels on nerve

membrane when applied to the outer membranous surface and produce conduction blockade

•Administered via subarachnoid block•250,000 as potent as procaine•But are difficult to synthesize and not

stable so limiting their usefulness

ELECTRONIC DENTAL ANESTHESIA•Alternative to la injections in most

procedures ,fillings ,cleaning etc•Possible to have pain control without being

numbed by a shot•We do this with a unit that is powered by a

battery ,two small sponges are placed in the patients mouth or on the face, which are attached to the control box that the patient uses to select the depth of anesthesia

EDA UNITTREATMENT WITHOUT NEED FOR LA

INDICATIONS•Patient having needle phobia•Ineffective la•Instances where la cannot be

administered( eg. allergy)• TMJ(chronic pain)•Nonsurgical periodontal pain•Restorative dentistry•Fixed prosthodontic procedure

CONTRAINDICATIONS•Cardiac pacemakersNeurological disorders•Pregnancy•Immaturity very young pediatric patient older patient with senile dementia language communication difficulties

ADVANTAGES•No need of needle•No need for injections of drugs•Patient is in control of the anesthesia•No residual anesthetic effect at the end of

procedure•Residual analgesic effect remains for

several hours

DISADVANTAGES•Cost of the unit•Training•‘Learning curve‘ initial success may be

low but increases with experience•Intraoral electrode:weak link in the entire

system

NEWER DRUGS•PHENTOLAMINE MESYLATE•ARTICAINE HCL

PHENTOLAMINE MESYLATE•It is short acting alpha adrenergic

antagonist receptors•Includes peripheral vasodilation and

tachycardia•Available as a 5mg/ml solution for

parenteral administration

•It is indicated in reversal of soft tissue anesthesia (eg. Anesthesia of lip and tongue) and associated functional difficults resulting from intraoral submucosal injection and local anesthetic containing vasoconstrictor

•Not recommended for use in children younger then 6 years of age or weighing less then 15 kg

•Treatment option whenever prolonged STA presents a potential risk(soft tissue injury) or will negatively impact the patient’s life style(eg. Inability to speak or eat)

ARTIICAINE HCL•It is infiltrated in buccal fold adjacent to

the 1st mandibular molar showing significantly greater success rate compared with lidocaine 2% infiltration

•minimal volume of LA solution needed to produce best clinical result recommended a full cartridge of artricain 4% with epinephrine 1: 100000

INTRA NASAL LA• The nares are extremely vascular so most drugs

instilled into them will be absorbed rapidly and systemically which numbs upper teeth in dental application

FOR EXAMPLE:• Snorting a line of COCAINE • CNS depressent drug MIDAZOLAM in management

of status epilepticus in young children • TETRACAINE used to provide a numbing effect

before surgical manipulation in the nose

•Vasoconstictor OXYMETHAZOLINE was added to the tetracaine to enhance the effectiveness which active ingredient in the nasal decongestant spray,Afrin

COMPUTER CONTROLLED LOCAL ANESTHETIC DELIVERY(C-CLAD)

COMFORT CONTROL SYRINGE SYSTEM

•It is electronic, preprogrammed deliverydevice that provides the operator with control needed to make patients LA injection experience as pleasant as possible

C-CLAD

LIGHT WEIGHT HAND PIECE FOR COMPUTER CONTROL LA DELIVERY

ADVANTAGES•Familiar syringe type of delivery system •Easy to see exactly how much LA solution

has been dispensed,just as on a manual syringe

•Inexpensive disposables•All control literally at fingertips

DISADVANTAGES•Requires additional armenterium•More bulky then other computer control

local (C-CLAD)manual LA device•Vibration may bother some users•costly

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